The Fossa alterna is similar to the ArborLoo but the slab and superstructure are alternately placed on one of two permanently sited shallow pits. Like the ArborLoo, wood ash and soil are added regularly and other materials like organic kitchen scraps, leaves, soil etc which promote the composting process. Once the first pit is nearly full the slab and superstructure are moved on to the second pit and the first pit is topped up with fertile soil. After a period of between six and twelve months the contents of the first pit will have changed into humus. The humus is dug out and used on the garden. The slab and superstructure are then moved back on to the first pit and the second pit is topped up with soil. This cycle is repeated time and time again.
Fossa alterna Chapter 1
Fossa alterna Chapter 2
Fossa alterna Chapter 3
Fossa alterna Chapter 4
Fossa alterna Chapter 5 (Published 30/12/2002 on the web)